Research Of Motion Estimation Algorithm In Video Compression

In multimedia-transmission and storage, as the image for video information needs a mount of bits, high quality of channel bandwidth and huge storage space are required. This has been one of the key points to get and use information efficiently. Motion estimate is the key skill in video coding, a way of between frames coding. It bases on the theory of temporal correlation between frames, to reduce temporal redundancy. An outstanding method of motion estimate can get an accurate motion vector. Finding out the most resembled part as the matching part in the neighbor by using the present part, pointing at it by motion vector, then finding out the different part between the matching part and the present part, at last rebuilding the compressed frame by the matching part and the different part, this process is called motion compensation. Therefore, in the video coding whose key skill is motion estimate, the speed of searching motion vectors and the accuracy of motion vectors are the most important factors to video effect.This thesis expatiates deeply and systematically on the basic theory of motion estimate technique. On the base of present classical algorithms, we focuses on researching the disadvantages of those existing algorithms of motion estimate, and initiating some new ways in our own view. The main content as follows:1. Summarize the current classical algorithms of motion estimate, present integrated experimental data and comparisons, trim and put forward some basic theories of motion estimate.2. Research motion estimate by phase correlation way, bring forward a new technique of motion estimate on the base of phase correlation.3. Study space-time correlation and center biased distribution of motion vector, on which initiate a new fast search algorithm of motion estimate.4. Research the blocking effect of block matching algorithms. Analyze deeply the reason of blocking effect, introduce and compare several measure criterions and theories and ways to reducing blocking effect. It is significant in both theoretics and practicality to combine themotion estimate technique and research of data compressed coding to solve the problem of huge information data in video, which is an important question for discussion in image processing field and image communication field. The research and application of it inevitably promote the development of computer communication, image communication and multi-media technique.